Developing hurricanes rely heavily on moisture and warm ocean surface temperatures to form. When ocean surface temperatures are decreased, the strength of a storm is also diminished, the scientists say in a study published in the August edition of the Atmospheric Science Letters journal.

Marine cloud brightening increases the reflectiveness of these clouds. This creates a cooling effect as more sunlight is reflected back into space, rather than heating up the ocean’s surface, Gadian says.

“When (tropical) storms go over the sea, if the sea surface is warm enough then you form a hurricane. The hurricane gets its energy from the very warm sea surface temperatures,” Gadian says.

“(With cloud seeding) you are basically cutting off the energy that supplies (a hurricane). You are turning down the heat.”

Gadian and his team focused on low-level, long-living maritime stratocumulus, or layer clouds, as they cover 30 per cent of the world’s oceans. The white, fluffy clouds are roughly 300 to 500 metres thick and have a height ranging from 800 to 1,200 metres.

Hurricanes mainly occur in August and September in the northern hemisphere when ocean surface temperatures are at their warmest.

The idea, Gadian says, is to keep the ocean surface temperatures slightly lower so a hurricane doesn’t have the energy needed to generate a category-five storm.

Gadian and his team found that the technique could drop ocean surface temperatures by a few degrees, and thereby reduce the severity of a hurricane by one category.

The scientists’ approach differs from the traditional idea of seeding clouds, which revolved around trying — often unsuccessfully — to control the weather, Gadian says.

This was evident in China at the 2008 Beijing Olympics.

Cloud seeding has also been used to protect wine vines from heavy hail in Bulgaria, with silver iodide being shot into clouds.

Gadian says more study is needed on the costs and drawbacks of marine cloud brightening before it could be put in place.

There also needs to be more research and development on how the process would work — in their study, the scientists discussed unmanned ships spraying the clouds.

One drawback Gadian foresees is the potential effect on rainfall in nearby areas where reduced rainfall could be problematic. For example, seeding in the Atlantic could affect rainfall in the Amazon basin, he says.